Best Fuel Mileage ???

[Mark(The Miser)UK]

i never get that kind of mileage out of my quantum...i'm consistently around 35mpg...no mods...any suggestions to help squeeze out some more mpg's?

Ideas in order of priority assuming injectors OK

1) Set timing exactly... wedge cam slop up with feeler gauges. Set pump to 1mm.

2) Use the 2" exhaust system from a 5 ganger gasser. Use a straight pipe for the snaked centre piece if you can find it.

3 ) Lift lid off spaceship and lean diaphragm. Drive and then gradually re-adjust until car responds sufficiently well for your driving style so that you don't have to hammer the accelerator to pass trucks...

4) Consider a different air filter...

[Mark(The Miser)UK]

92 Jetta 1.9TD/k14, tall gears, about 47 mpg imperial in the summer, less on winter fuel. Exhaust is stright through, 2", no mufflers or resonators.

92Jetta 1.6TD/k24 standard gears, about 50 mpg imperial summer, less in winter. Factory toilet bowl, and full exhaust. Compression last fall about 420 across all 4 holes. Timing at .42.......

Both cars running lots of air pressure, no air conditioning.

Can't seem to get any better..........

[/size]
Do you have any data for the 1.9 with a smaller exhaust?
Are these 'bests' or average 'mpg's

[aidan]

My first tank gave me 57mpg (UK), that was about 590 miles to about £38 (around 89-90p per litre)
For roughly the same money i've had 500, 570 and a couple in between.

I'm extremely happy with that as I have come from a VR6, and that was about 350miles to £50


PS this is a 1991 J Golf GTD with 147k miles on it

[Mark(The Miser)UK]

Aidan this is the GTD I've just bought for my mother-in-law.
PO was claiming about 40-50mpg 'biggals'
This seems a little poor to me. The car as you can see is pretty tidy. I suspect that the car is detuned as it is a little sluggish at low revs...

http://img110.imageshack.us/my.php?image=mygtdyo5.jpg

[aidan]

It looks like mine should, add a bent bumper, rust patches and slightly more pink paintwork and it would be mine as it is now!

Most of my miles are at around 65 on the motorway, around 50 miles per day, with around 10-15 round town with no queues, so generally quite hard on it. I've only had it about 5-6 weeks but done around 2500 miles on it.

I find it is sluggish at low revs to be honest, judders a bit if your not around 1800 or above. Not bad otherwise

[Mark(The Miser)UK]

I find it is sluggish at low revs to be honest, judders a bit if your not around 1800 or above. Not bad otherwise

Just went out and lifted the lid on the spaceship... Boost was set to a little below half way round (I'm talking the offset cone here) as is factory [should be].
 Note the position of the little dimple on the black diaphragm.  Look at the trace left by the lever as it follows the tapered cone rotate till maximum machining/offset is facing lever. Replace and go for a spin. If smoking then perhaps back off towards first position.  If not enough power then it needs to be the 'collered' fuel screw in a little...
For me there  is now still no smoking and the lag has all but disappeared.

Just noticed that there is a slight oil leak from the head gasket. May have been there for a while... Coolant slightly low so I'll keep an eye on it. Didn't check it 80 miles ago. Duhh  :roll:  
As long as there are no other problems :shock:

 Granny is now commiting herself to the car by transferring her insurance tomorrow. :cry:

[aidan]

I intend to start tampering with the pump and boost this weekend as a boost gauge is in the post.

Funny you should mention the head gasket, i've got hard smoky starting (gets better the more I cycle the plugs) and the expansion tank was still pressurised long after switching off.
I'm hoping the new blue tank cap and reseating the injectors (very slight leak at the head) may solve

[Mark(The Miser)UK]

Best check for pressure is to crank over for a few seconds from cold and then listen for a psst when opening cap

[aidan]

Well I took that cap off just then, plenty of air escaping then.

Then put the cap back on, cranked for a few seconds, opened the cap and nothing. No overheating, no using oil or coolant, no sign of oil in the coolant or vice versa. Anyway, thats for the troubleshooting section I guess.

At the same time was going to have at go at lifting the lid as you did, well not one of my screwdrivers will loosen them screws! I should have another round somewhere with a larger head on it

[95gltd]

Yes, that's with my 97 Jetta 1.9TD. Why?

Now mind you.....that's driving it conservatively (shifting at about 2500, staying at 100 km/h or 60mph on the highway etc). Harder driving (shifting over 3000 and doing 70mph on the highway) drops it to 50-52 mpg.

I average 42mpg(imperial) in the winter and maybe 1 mpg better in the summer. Always shifting @ 2000rpm. Sometimes a little higher on a big hill never over 2600rpm. Tires blown up to correct pressure. New air filter/fuel filter,rebuilt turbo. I did see around 52pmg with my old 85 1.6 n/a diesel.

You must see around 1050km on a tank?

I need some help with my golf. I took it to the vw shop last fall to get the timeing on the pump set. Now i have to run with the handle out or at speed on the highway it skips like it goes from 4-3 cyls then back. I'm thinking my injectors might be bad. Would bad injectors cost over 5 mpg?

[Mark(The Miser)UK]

What does it idle like?

[aidan]

Mark,
Just rotated the boost pin, though was a little confused by a few parts of your instructions.

The little dimple firstly, thats on the metal that surrounds the black diaphragm right, not on the diaphragm itself?
Trace, well don't know what you mean by trace.
Finally when you say lever I assume you were referring to the main 'throttle' lever for want of a better term?

Anyway, the maximum machined bit and dimple are facing the lever, or in line with the bottom left screw as you look at of the spaceship. Went for a spin and to be honest didn't feel any different.

Your quote;
Just went out and lifted the lid on the spaceship... Boost was set to a little below half way round (I'm talking the offset cone here) as is factory [should be].
Note the position of the little dimple on the black diaphragm. Look at the trace left by the lever as it follows the tapered cone rotate till maximum machining/offset is facing lever. Replace and go for a spin. If smoking then perhaps back off towards first position.

[jtanguay]

Yes, that's with my 97 Jetta 1.9TD. Why?

Now mind you.....that's driving it conservatively (shifting at about 2500, staying at 100 km/h or 60mph on the highway etc). Harder driving (shifting over 3000 and doing 70mph on the highway) drops it to 50-52 mpg.

I average 42mpg(imperial) in the winter and maybe 1 mpg better in the summer. Always shifting @ 2000rpm. Sometimes a little higher on a big hill never over 2600rpm. Tires blown up to correct pressure. New air filter/fuel filter,rebuilt turbo. I did see around 52pmg with my old 85 1.6 n/a diesel.

You must see around 1050km on a tank?

I need some help with my golf. I took it to the vw shop last fall to get the timeing on the pump set. Now i have to run with the handle out or at speed on the highway it skips like it goes from 4-3 cyls then back. I'm thinking my injectors might be bad. Would bad injectors cost over 5 mpg?

well it can cost you that, and some pistons maybe???  i had some work done on my car and the guy who did it said that my pistons were melting on the outer edges.. most likely from high egt's and bad injector spray pattern... but my glowplugs are fine! go figure.